Plasmalogenase activities are markedly increased in the early stages of many forms of demyelination. The gerbil model for cerebral infarction will be used. Plasmalogenase and other phospholipases will be studied at various times after ligation of carotid arteries. Preliminary studies have given a peak activation of plasmalogenase at 20 minutes of ligation. Within te brain, the plasmalogenase is primarily within the particulate portion of the oligodendroglia. We will determine the subcellular location. Plasmalogenase has been partially purified. We intend to compare plasmalogenase purified from control and ligated brains. Cultured cells and tissues will be used to test possible activators and inhibitors of plasmalogenase. Inhibitors will be tested with the gerbil model in order to find a therapeutic agent that may prevent demyelination.